Hydrophytic plants have adapted to thrive in wetlands despite the stresses of an anaerobic and flooded environment. Most upland plants take in oxygen through root systems and distribute it through their stems and leaves. To succeed in their waterlogged environment, wetland plants must employ other strategies such as long, oxygen-transporting tubes (emergent reeds), the ability to float on shallow water (lilies), or buttressed trunks (cypress trees). Plants are often the most obvious indicators of a wetland.

Most of the obvious wetland plant adaptations have to do with capturing and transporting oxygen. Look for clues like:

1. "Knees" in a tree's root system that jut our of the ground and extend above the high water mark, where they may take in oxygen (cypress).
2. Shallow or exposed roots that pick up oxygen from surface, aerobic soil layers.
3. Plants with hollow tubes or sacs that transport oxygen to the roots (reeds, grasses, sedges).
4. Buoyant, floating plants with root systems that dangle in the water
5. Swollen (buttressed) tree trunks that are usually thickened to the height of deepest water inundation.